Conventional barbecue kettles for cookout are structurally either rectangular or round with their bottoms centrally concave and basin-like where the roasting grill, charcoal support grill and, in some cases, kettle lid are provided. They have common shared features. In making a fire, fire seeds or fire-initiating materials are firstly placed on the bottom of the barbecue kettle, then the charcoal grill and charcoals are put in place, and when the charcoal has been ignited, the flat roasting grill, which can bear various food to be cooked is put in place. Yet if roasting a full chicken is desired, the roasting grill must be removed to create sufficient space to allow that roasting to occur. Though usable, such conventional barbecue kettles are found to have the following shortcomings:
1. Because the roasting grill is flat and can do flat-roasting only, an evenly roasted degree to all parts of the roasted object requires manual adjustment of the food. That turns out to be especially troublesome when cooking smaller pieces of food which need to be turned over one by one.
2. Because the roasting grill must be removed to allow roasting a full chicken, the problem of how to securely settle it for roasting arises. And the heat force, surrounding full chicken inside the barbecue kettle, would then no longer be used.
3. During roasting time of a full chicken, the kettle lid, if any, must be taken down to allow dressings application to the chicken's surfaces. Removal of the lid doubtless causes a quicker loss of heat and lengthens the roasting time.
4. To provide charcoals during roasting time, the kettle lid, roasted objects and roasting grill all have to be removed or moved aside to enable placement of fresh charcoal onto the charcoal grill.
5. The force of the fire inside the kettle is under full control.
6. To make a fire, charcoal grill and roasting grill both have to be removed away to allow ignition of the fire seeds or fire-initiating materials at the kettle bottom. Furthermore, in case of fire failure, the half-combusted charcoals must be taken out and that may easily cause burning.